Hitherto, when articles susceptible to damage when the articles are tumbled over, for example, precision instruments such as video cameras or hard disks, are transported, a tumble detector that detects a tumble of an article has been attached to a container (an article) that holds many precision instruments so as to detect whether the article has been tumbled over during transportation. Tumble detectors of such a type include a tumble detector that incorporates an electrical circuit for recording and displaying the time when a tumble has occurred. Although a new function can be added to the tumble detector by incorporating the electrical circuit, the cost of the tumble detector increases. Tumble detectors in which it can be detected whether an article has been tumbled over during transportation and the cost is reduced include those described in U.S. Pat. Nos. 4,438,720 and RE32,570.
FIG. 16 shows a status in which a known tumble detector 10 is attached to a container 20 that holds many precision instruments. In FIG. 16, in view of a tumble of the container 20 in the forward-backward direction and the left-right direction, the tumble detector 10 is attached to each of the two adjacent sides of the container 20.
The known tumble detector 10 is similar in the basic principle to those described in U.S. Pat. Nos. 4,438,720 and RE32,570. The known tumble detector 10 includes a disk 15 that rolls (i.e., rotates) in response to the inclination, a pair of inclined guides 25 and 30 that retain the disk 15 in a case 20, an auxiliary guide 35 that assists the disk 15 to roll on the inclined guides 25 and 30, a cover 40 that covers the case 20, and an adhesive tape 45 for attaching the back face of the case 20 to an article, as conceptually shown in a front elevational view and Section A-A in FIG. 17. The disk 15 is composed of a single metal plate. The pair of inclined guides 25 and 30 and the auxiliary guide 35 are composed of synthetic resin such as plastic using a rib structure in which the pair of inclined guides 25 and 30 and the auxiliary guide 35 are formed integrally with the case 20.
When the container 20 is tumbled over, so that the tumble detector 10 inclines, for example, leftward to be tumbled over, the disk 15 rolls on and moves away from the inclined guide 25, as shown in Part (a) of FIG. 18. Even when the tumble detector 10 is returned to the original position by raising the tumbled over container 20 to a position shown in FIG. 16, the disk 15 remains at the bottom of the tumble detector 10 and is not returned to the initial position, shown in FIG. 17, where the disk 15 has been retained by the pair of inclined guides 25 and 30, as shown in Part (b) of FIG. 18.
In this way, after the container 20 is tumbled over, even when the container 20 is returned to the original position, the disk 15 remains at the bottom of the tumble detector 10 and is not returned to the initial position. Thus, it can be detected whether the container 20 has been tumbled over during transportation by checking the position of the disk 15 in the case 20 after the container 20 is transported.
Patent Document 1: U.S. Pat. No. 4,438,720
Patent Document 2: U.S. Pat. No. RE32,570